The present invention relates to a support system for combustion liners in a gas turbine combustion system and particularly relates to supports interconnecting the upstream ends of a combustion liner to the surrounding flow sleeve or other surrounding structure for reducing wear between the contact surfaces of the parts while maintaining axial, circumferential and radial position of the liner.
In an existing system for supporting a liner within a flow sleeve, three equally spaced tab and slot arrangements are disposed about the upstream end of the combustor between the flow sleeve and liner. A tab and slot arrangement is used to ensure proper positioning of the components and to facilitate assembly. However, combustion pressure oscillations and buffeting due to external and internal air flow can result in relative motion between the tab and slot contact surfaces. This relative motion produces wear on the parts. Currently, combustion inspection intervals are determined in part by the amount of wear that can be permitted before repair is required. Extension of the inspection interval is desirable to reduce operation and maintenance costs and to increase machine availability.
Prior attempts at reducing wear focused on using wear-resistant materials and closely controlled clearances and tolerances between contacting surfaces. That design philosophy, however, has not proven completely successful in reducing wear on the combustor supports. It will be appreciated that various design constraints are imposed on the support system between the liner and the surrounding structural components For example, both relative thermal expansion and manufacturing tolerances of the flow sleeve and liner must be accommodated.